| BackgroundMacrophage colony stimulating factor(M-CSF)is a kind of cytokine which plays a key regulatory role in the immune system,and it can activate and enhance the killing effect of macrophages and stimulate pinocytosis.Recent studies have shown that M-CSF not only assists in maintaining a stable state of normal physiological activity,but also has been proved to be highly expressed in various types of cancer with its receptor M-CSFR,including kidney cancer and bladder cancer.Under the recruitment of M-CSF,a large number of tumor-related macrophages infiltrated into the internal environment and were further polarized into the M2 subtype.Activated macrophages accelerate the growth and invasion of cancer cells by promoting the production and secretion of various immune molecules.PurposeAt present,there are only a few studies explored the formation mechanism of high expression of M-CSF in ovarian cancer microenvironment and its roles in regulating macrophage polarization and aggregation.Through laboratory cytology and histopathological analysis,we systematically detected the mechanism of polarization and aggregation of macrophages in tumor tissues induced by M-CSF,and further explored the regulatory effects of M-CSF on the invasion and metastasis of ovarian tumor cells.MethodsThe indirect co-culture system of A2780 and SKOV3 human ovarian cancer cells and mononuclear macrophages was established in the in vitro environment of simulator.The concentration and transcriptional level of M-CSF in culture supernatant were detected by ELISA(enzyme linked immunosorbent assay)and q RT-PCR(Real-time quantitative PCR).The specific phenotypes of M2-type macrophages were identified by flow cytometry.Cell migration experiments were conducted to compare the effects of co-culture medium on chemotaxis migration of A2780 and SKOV3 cells.Immunohistochemistry was used to identify M-CSF,CD68,CD163 and E-CAD in pathological sections of 52 cases of ovarian cancer and 18cases of benign ovarian tumors.The correlation between the expression of M-CSF and various clinicopathological parameters was analyzed,and the correlation between the detection indicators was compared.ResultsCompared with the A2780 and SKOV3 human ovarian cancer cells cultured alone,the concentration of M-CSF in the indirect co-culture system was significantly increased,and the difference was statistically significant(P<0.01).The results were further verified by q RT-PCR,and the elevated M-CSF was derived from the synthesis and release of ovarian cancer cells under co-culture conditions(P<0.05).Flow cytometry analysis showed that co-culture microenvironment with the two types of ovarian cancer cells could induce the transformation of macrophages into CD68 and CD163 positive M2 subtypes(P<0.01).Transwell analysis showed that the migration activity of A2780 and SKOV3 cells after co-culture was significantly increased(P<0.01).The expression intensity of M-CSF,CD68 and CD163 in ovarian cancer tissues was significantly higher than that in benign tumors(P<0.01),while E-Cad staining score was significantly lower in the control group(P<0.01).Univariate analysis showed that the expression level of M-CSF was closely related to clinical diagnosis of tumor stage,differentiation,and lymph node metastasis(all P<0.05).M-CSF staining score was significantly positively correlated with CD68~+and CD163~+cell count(all P<0.001),but negatively correlated with E-Cad positive expression(P<0.001).ConclusionM-CSF recruited macrophages to aggregate in tumor tissues and induced their polarization towards the M2 subtype,which further promotes the infiltration and migration of cancer cells.This suggests the potential value of M-CSF in immunoadjuvant therapy for ovarian cancer. |
PDF Full Text Request